The disease or group of diseases described generally as helminthiasis is due to infection of an animal host with parasitic worms known as helminths. Helminthiasis is a widespread and serious economic problem in livestock animals such as swine, sheep, horses, cattle, goats, and poultry. Helminthiasis is also a serious health risk to humans and companion animals such as dogs, cats and other pets.
Among the helminths, the group of worms described as nematodes causes widespread, and often times serious, infection in various species of animals. Several of the more common genera of nematodes infecting the digestive systems of the animals referred to above are Ascaris, Haemonchus, Ostertagia, Oesophagostomum, Cooperia, Strongyloides, and Trichostrongylus. Certain helminths, such as Cooperia and Oesophagostomum, attack primarily the intestinal tract, while others, such as Haemonchus and Ostertagia are more prevalent in the stomach. Haemonchus and Ostertagia sp. are costly parasites in the cattle, sheep and goat industries.
The adverse economic impacts on agriculture of the parasitic infections known as helminthiases are well known. Helminth infections interfere with animal digestion and nutrient absorption and thus cause anemia, malnutrition, weakness, and weight loss. Helminths can also cause severe damage to the walls of the gastrointestinal tract and other tissues and organs and, if left untreated, may result in death of the infected host animal. Accordingly, infected livestock will exhibit poor production performance as manifested by little or no weight gain, metabolic disturbances, reproductive abnormalities, and reduced milk production and quality.
Parasitic infections detract also from the quality of human and companion animal life. In addition, the impact on humans is particularly severe in third world nations. Helminthiasis causes similar symptoms in humans and companion animals to those found in livestock, including nausea, diarrhea, anemia, malnutrition, weight loss, weakness, and, in severe cases, death.
What is needed are improved methods for the treatment of helminthiases in animals such as livestock species.